var RENDERER = {
  POINT_INTERVAL : 5,
  FISH_COUNT : 6,
  MAX_INTERVAL_COUNT : 50,
  INIT_HEIGHT_RATE : 0.5,
  THRESHOLD : 50,

  init : function(){
    this.setParameters();
    this.reconstructMethods();
    this.setup();
    this.bindEvent();
    this.render();
  },
  setParameters : function(){
    this.$window = $(window);
    this.$container = $('#jsi-flying-fish-container');
    this.$canvas = $('<canvas />');
    this.context = this.$canvas.appendTo(this.$container).get(0).getContext('2d');
    this.points = [];
    this.fishes = [];
    this.watchIds = [];
  },
  createSurfacePoints : function(){
    var count = Math.round(this.width / this.POINT_INTERVAL);
    this.pointInterval = this.width / (count - 1);
    this.points.push(new SURFACE_POINT(this, 0));

    for(var i = 1; i < count; i++){
      var point = new SURFACE_POINT(this, i * this.pointInterval),
        previous = this.points[i - 1];

      point.setPreviousPoint(previous);
      previous.setNextPoint(point);
      this.points.push(point);
    }
  },
  reconstructMethods : function(){
    this.watchWindowSize = this.watchWindowSize.bind(this);
    this.jdugeToStopResize = this.jdugeToStopResize.bind(this);
    this.startEpicenter = this.startEpicenter.bind(this);
    this.moveEpicenter = this.moveEpicenter.bind(this);
    this.reverseVertical = this.reverseVertical.bind(this);
    this.render = this.render.bind(this);
  },
  setup : function(){
    this.points.length = 0;
    this.fishes.length = 0;
    this.watchIds.length = 0;
    this.intervalCount = this.MAX_INTERVAL_COUNT;
    this.width = this.$container.width();
    this.height = this.$container.height();
    this.fishCount = this.FISH_COUNT * this.width / 500 * this.height / 500;
    this.$canvas.attr({width : this.width, height : this.height});
    this.reverse = false;

    this.fishes.push(new FISH(this));
    this.createSurfacePoints();
  },
  watchWindowSize : function(){
    this.clearTimer();
    this.tmpWidth = this.$window.width();
    this.tmpHeight = this.$window.height();
    this.watchIds.push(setTimeout(this.jdugeToStopResize, this.WATCH_INTERVAL));
  },
  clearTimer : function(){
    while(this.watchIds.length > 0){
      clearTimeout(this.watchIds.pop());
    }
  },
  jdugeToStopResize : function(){
    var width = this.$window.width(),
      height = this.$window.height(),
      stopped = (width == this.tmpWidth && height == this.tmpHeight);

    this.tmpWidth = width;
    this.tmpHeight = height;

    if(stopped){
      this.setup();
    }
  },
  bindEvent : function(){
    this.$window.on('resize', this.watchWindowSize);
    this.$container.on('mouseenter', this.startEpicenter);
    this.$container.on('mousemove', this.moveEpicenter);
    this.$container.on('click', this.reverseVertical);
  },
  getAxis : function(event){
    var offset = this.$container.offset();

    return {
      x : event.clientX - offset.left + this.$window.scrollLeft(),
      y : event.clientY - offset.top + this.$window.scrollTop()
    };
  },
  startEpicenter : function(event){
    this.axis = this.getAxis(event);
  },
  moveEpicenter : function(event){
    var axis = this.getAxis(event);

    if(!this.axis){
      this.axis = axis;
    }
    this.generateEpicenter(axis.x, axis.y, axis.y - this.axis.y);
    this.axis = axis;
  },
  generateEpicenter : function(x, y, velocity){
    if(y < this.height / 2 - this.THRESHOLD || y > this.height / 2 + this.THRESHOLD){
      return;
    }
    var index = Math.round(x / this.pointInterval);

    if(index < 0 || index >= this.points.length){
      return;
    }
    this.points[index].interfere(y, velocity);
  },
  reverseVertical : function(){
    this.reverse = !this.reverse;

    for(var i = 0, count = this.fishes.length; i < count; i++){
      this.fishes[i].reverseVertical();
    }
  },
  controlStatus : function(){
    for(var i = 0, count = this.points.length; i < count; i++){
      this.points[i].updateSelf();
    }
    for(var i = 0, count = this.points.length; i < count; i++){
      this.points[i].updateNeighbors();
    }
    if(this.fishes.length < this.fishCount){
      if(--this.intervalCount == 0){
        this.intervalCount = this.MAX_INTERVAL_COUNT;
        this.fishes.push(new FISH(this));
      }
    }
  },
  render : function(){
    requestAnimationFrame(this.render);
    this.controlStatus();
    this.context.clearRect(0, 0, this.width, this.height);
    //this.context.fillStyle = 'hsl(0, 0%, 95%)';
    this.context.fillStyle = 'hsl(204,70%,95%)';

    for(var i = 0, count = this.fishes.length; i < count; i++){
      this.fishes[i].render(this.context);
    }
    this.context.save();
    this.context.globalCompositeOperation = 'xor';
    this.context.beginPath();
    this.context.moveTo(0, this.reverse ? 0 : this.height);

    for(var i = 0, count = this.points.length; i < count; i++){
      this.points[i].render(this.context);
    }
    this.context.lineTo(this.width, this.reverse ? 0 : this.height);
    this.context.closePath();
    this.context.fill();
    this.context.restore();
  }
};
var SURFACE_POINT = function(renderer, x){
  this.renderer = renderer;
  this.x = x;
  this.init();
};
SURFACE_POINT.prototype = {
  SPRING_CONSTANT : 0.03,
  SPRING_FRICTION : 0.9,
  WAVE_SPREAD : 0.3,
  ACCELARATION_RATE : 0.01,

  init : function(){
    this.initHeight = this.renderer.height * this.renderer.INIT_HEIGHT_RATE;
    this.height = this.initHeight;
    this.fy = 0;
    this.force = {previous : 0, next : 0};
  },
  setPreviousPoint : function(previous){
    this.previous = previous;
  },
  setNextPoint : function(next){
    this.next = next;
  },
  interfere : function(y, velocity){
    this.fy = this.renderer.height * this.ACCELARATION_RATE * ((this.renderer.height - this.height - y) >= 0 ? -1 : 1) * Math.abs(velocity);
  },
  updateSelf : function(){
    this.fy += this.SPRING_CONSTANT * (this.initHeight - this.height);
    this.fy *= this.SPRING_FRICTION;
    this.height += this.fy;
  },
  updateNeighbors : function(){
    if(this.previous){
      this.force.previous = this.WAVE_SPREAD * (this.height - this.previous.height);
    }
    if(this.next){
      this.force.next = this.WAVE_SPREAD * (this.height - this.next.height);
    }
  },
  render : function(context){
    if(this.previous){
      this.previous.height += this.force.previous;
      this.previous.fy += this.force.previous;
    }
    if(this.next){
      this.next.height += this.force.next;
      this.next.fy += this.force.next;
    }
    context.lineTo(this.x, this.renderer.height - this.height);
  }
};
var FISH = function(renderer){
  this.renderer = renderer;
  this.init();
};
FISH.prototype = {
  GRAVITY : 0.4,

  init : function(){
    this.direction = Math.random() < 0.5;
    this.x = this.direction ? (this.renderer.width + this.renderer.THRESHOLD) : -this.renderer.THRESHOLD;
    this.previousY = this.y;
    this.vx = this.getRandomValue(4, 10) * (this.direction ? -1 : 1);

    if(this.renderer.reverse){
      this.y = this.getRandomValue(this.renderer.height * 1 / 10, this.renderer.height * 4 / 10);
      this.vy = this.getRandomValue(2, 5);
      this.ay = this.getRandomValue(0.05, 0.2);
    }else{
      this.y = this.getRandomValue(this.renderer.height * 6 / 10, this.renderer.height * 9 / 10);
      this.vy = this.getRandomValue(-5, -2);
      this.ay = this.getRandomValue(-0.2, -0.05);
    }
    this.isOut = false;
    this.theta = 0;
    this.phi = 0;
  },
  getRandomValue : function(min, max){
    return min + (max - min) * Math.random();
  },
  reverseVertical : function(){
    this.isOut = !this.isOut;
    this.ay *= -1;
  },
  controlStatus : function(context){
    this.previousY = this.y;
    this.x += this.vx;
    this.y += this.vy;
    this.vy += this.ay;

    if(this.renderer.reverse){
      if(this.y > this.renderer.height * this.renderer.INIT_HEIGHT_RATE){
        this.vy -= this.GRAVITY;
        this.isOut = true;
      }else{
        if(this.isOut){
          this.ay = this.getRandomValue(0.05, 0.2);
        }
        this.isOut = false;
      }
    }else{
      if(this.y < this.renderer.height * this.renderer.INIT_HEIGHT_RATE){
        this.vy += this.GRAVITY;
        this.isOut = true;
      }else{
        if(this.isOut){
          this.ay = this.getRandomValue(-0.2, -0.05);
        }
        this.isOut = false;
      }
    }
    if(!this.isOut){
      this.theta += Math.PI / 20;
      this.theta %= Math.PI * 2;
      this.phi += Math.PI / 30;
      this.phi %= Math.PI * 2;
    }
    this.renderer.generateEpicenter(this.x + (this.direction ? -1 : 1) * this.renderer.THRESHOLD, this.y, this.y - this.previousY);

    if(this.vx > 0 && this.x > this.renderer.width + this.renderer.THRESHOLD || this.vx < 0 && this.x < -this.renderer.THRESHOLD){
      this.init();
    }
  },
  render : function(context){
    context.save();
    context.translate(this.x, this.y);
    context.rotate(Math.PI + Math.atan2(this.vy, this.vx));
    context.scale(1, this.direction ? 1 : -1);
    context.beginPath();
    context.moveTo(-30, 0);
    context.bezierCurveTo(-20, 15, 15, 10, 40, 0);
    context.bezierCurveTo(15, -10, -20, -15, -30, 0);
    context.fill();

    context.save();
    context.translate(40, 0);
    context.scale(0.9 + 0.2 * Math.sin(this.theta), 1);
    context.beginPath();
    context.moveTo(0, 0);
    context.quadraticCurveTo(5, 10, 20, 8);
    context.quadraticCurveTo(12, 5, 10, 0);
    context.quadraticCurveTo(12, -5, 20, -8);
    context.quadraticCurveTo(5, -10, 0, 0);
    context.fill();
    context.restore();

    context.save();
    context.translate(-3, 0);
    context.rotate((Math.PI / 3 + Math.PI / 10 * Math.sin(this.phi)) * (this.renderer.reverse ? -1 : 1));

    context.beginPath();

    if(this.renderer.reverse){
      context.moveTo(5, 0);
      context.bezierCurveTo(10, 10, 10, 30, 0, 40);
      context.bezierCurveTo(-12, 25, -8, 10, 0, 0);
    }else{
      context.moveTo(-5, 0);
      context.bezierCurveTo(-10, -10, -10, -30, 0, -40);
      context.bezierCurveTo(12, -25, 8, -10, 0, 0);
    }
    context.closePath();
    context.fill();
    context.restore();
    context.restore();
    this.controlStatus(context);
  }
};
$(function(){
  RENDERER.init();
});
